Question

In triunghiul dreptunghic ABC m(unghiului A)=90°, AD _|_ BC , D∈(BC), cos(unghiului DAB)=1/2 si AD=12 cm.Aflati aria si perimetrul triunghiului ABC.URGEENT!

Answer 1

cos (<DAB)=1/2
AD/AB=1/2
12/AB=1/2
AB=12*2=24 cm
m(<ABD)=90⁰-60⁰=30⁰
m(<ACB)=90⁰-30⁰=60⁰
sin 60⁰=√3/2
12/AC=√3/2
AC=24/√3=24√3/3=8√3 cm
BC=√(24²+8√3²=√(576+192)=√768=16√3
A=24*8√3/2=96√3 cm²
P=24+8√3+16√3=24+24√3=24(1+√3) =cm